User talk:AndrewJohnson
This page contains my notes from various meetings.
Notes
EPICS V4 Core
Interface Manager - need something to register and find interfaces.
- Could we generate a hash of the interface definition? Would allow us to compare interfaces and match two.
V4 Driver Interface
- Asyn Driver interfaces are now standardized, and are a good prototype for the V4 driver interface.
- In V4 the record types will directly talk to these driver interfaces.
- Hence device support will disappear in V4
Kay: These queryable interfaces are more like COM, although it seems that there is a difference in that in COM everything implements an interface that you can use to query what other interfaces an object implements.
We currently have interfaces for:
- value interface, for doing I/O and finding out about the value width, includes a "value changed" registration interface used for I/O Interrupt
- connection interface, for connecting/dis-connecting devices
- Address parser? or is that part of connection?
Kay's point; device support needs to be able to introspect the record it belongs to, to get the scan rate for instance, or the display limits. Solution: give the driver the record's name (or some other record pointer) to allow the driver to use the db access routines to get at this data.
However, don't try to include all of the asyn model into base.
Might use a record with a value field being a Map, which we then use for reading and/or writing device configuration data.
Software Registration
Replacement for registrar() which requires that the code implements a basic interface. Maybe this includes a use counter, as well as reporting, interface queries?
Redundancy Requirements
Goal: 5 second fail-over to backup system Limit: 15 seconds
